1. Field of the Invention
The present invention relates to a device for protecting an electronic component, for example, an electronic component attached to a printed circuit, to avoid any access to said electronic component or to data contained in said electronic component.
2. Discussion of the Related Art
Certain electronic circuits, for example, a chip card or magnetic card reader, comprise a printed circuit contained in a package. Electronic components may be soldered on both surfaces of the printed circuit. The system for example is a display screen, a serial connector, a connector intended to be connected to the telephone network, a memory card connector, etc. The printed circuit surface on which the display screen is attached is called the front surface and the printed circuit surface opposite to the front surface is called the rear surface.
The safety regulations prescribed by approval bodies generally impose to provide protection devices enabling to prevent the access to certain electronic components attached to the printed circuit. In particular, for certain electronic components attached to the rear surface of the printed circuit, safety regulations may impose the presence of specific protection devices for these components. Indeed, such components are more “sensitive” to fraud attempts since a user who manipulates the electronic system generally faces the screen and may not notice that a fraud attempt has been performed by drilling of the package on the rear surface side of the printed circuit.
An example of a protection device conventionally used to protect an electronic component such as a memory card connector comprises a rigid cage, attached to the printed circuit, which covers the connector while enabling access to the connector for the introduction of memory cards. The internal surfaces of the cage may be covered with a flexible protection circuit formed of the stacking of several flexible films between which are arranged interconnected conductive tracks, and forming at least one safety circuit. The safety circuit is connected at its ends to a processing system, provided at the printed circuit level. The processing system is capable of detecting the rupture of a conductive track of the safety circuit, which may correspond to an intrusion attempt.
The connections between the cage and the printed circuit may be arranged between the electronic component protected by the cage and the printed circuit so that they are not accessible. A disadvantage is that it is then not possible to assemble or disassemble the cage independently from the electronic component. It may however be desirable, in the case where the cage does not function properly, to be able to remove the cage independently from the electronic component to replace it with a cage which functions properly. For this purpose, the connections between the cage and the printed circuit may be arranged at the cage periphery to assemble or disassemble the cage independently from the electronic component. However, in this case, the connections between the cage and the printed circuit can be accessible from the outside of the cage. Someone could then short-circuit the safety circuit of the cage via these connections to be able to remove the cage without for this to be detected by the printed circuit processing system. The electronic component would then be accessible.
Document DE-A-10312654 describes a protection system in which a cap covering an electronic circuit is assembled to the printed circuit supporting the circuit by non-conductive pins engaged in holes of the printed circuit.